lO NEW YORK STATE MUSEUM 



the vicinity of Black lake. The uplift was accompanied by dislo- 

 cations of the peneplain surface, owing to movements along the 

 great fault planes of the region, which broke up the uniform sur- 

 face into a mosaic of flat-topped blocks at varying levels. Because 

 of this dislocation and the modifying effects of subsequent erosion, 

 the recognition of the peneplain surface in the eastern Adirondacks 

 is a matter of considerable difficulty. The western Adirondacks 

 were uplifted without dislocation, and there the peneplain is easily 

 recognized. 



The Adirondack highland is a moderately rugged .region with 

 much bare rock and comparatively little good soil, and is forest- 

 covered throughout. In winter it is tenanted by the lumberman, 

 in summer by the tourist and the river-driver. The population 

 is scanty and scattered. The region is strangely poor in mineral 

 wealth. But the forest and the water power are of great value ; 

 and no less so are the invigorating climate and the charm and 

 beauty of wood and water. 



THE MOHAWK LOWLAND 



Since the uplift of the Mesozoic peneplain, the weaker rocks 

 of the region have been deeply eroded. Along belts of weak rock, 

 valleys have been carved, the valley bottoms representing the 

 beginning of development of a new and lower peneplain. Not far 

 south of the ^Adirondacks runs a great, east-west belt of weak 

 shales, and into them the valley of the Mohawk has been carved 

 as a great belt of lowland between the Adirondack plateau on the 

 north and the plateau of southern New York. Great faults cross 

 the valley bringing up masses of more resistant rock, as at Little 

 Falls, St Johnsville, Sprakers, Tribes Hill and Hoffmans Ferry, 

 and in these the lower valley narrows and its walls steepen. Other- 

 wise the valley is broad and wide. 



East of Hoffmans it becomes especially wide, on approach to 

 the region of deformed rocks of eastern New York, in which the 

 strike of the rocks approximates a north-south direction. The 

 l)elt of shale broadens northward, curving around to merge with 

 the Hudson valley lowland. 



HUDSON VALLEY LOWLAND 

 From Fort Edward to Poughkeepsie the Hudson occupies a 

 broad, often very broad, valley eroded in a belt of soft shales. 

 (juite similar to the Mohawk valley, The shales are also of quite 



